JP2771859B2 - Endoscope device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an endoscope apparatus which drives an illumination means provided on a distal end portion at a predetermined frequency or higher.

[Prior Art] Recently, a video endoscope using a solid-state imaging device such as a CCD as an imaging means has been practically described.

Japanese Patent Application Laid-Open No. 60-217327 discloses a conventional example of a video endoscope in which a solid-state image sensor as an image pickup means and a solid-state light-emitting element for illuminating a subject are provided at the distal end of the endoscope. .

In this conventional example, the driving power is supplied from the power supply side to the solid-state light emitting element at the distal end by illuminating the subject by receiving the light emitting element, capturing an image by the CCD provided at the distal end of the endoscope, and imaging the subject on the monitor screen. Shows the technology to display.

In this conventional example, a light emitting element that emits red, green, and blue light is provided, and an example of image display by a color sequential method is shown.

In Japanese Utility Model Laid-Open Publication No. Sho 52-66188, the light emitting devices 1, 2, and 3 shown in FIGS. 11 and 12 are provided.

A semiconductor chip 4 in which light-emitting elements 1, 2, and 3 that emit blue, green, and red light and a drive circuit for driving the light-emitting elements are integrated is enclosed in a package 5 having at least an emission end. The lead wires 6, 7, 8, 9, 10 introduced into the package 5 are connected to the terminals of the drive circuit incorporated in the semiconductor chip and the conductors 11, 12,
Connected via 13,14.

FIGS. 13 and 14 show a driving circuit for the light emitting elements 1 ', 2' and 3 '.

The input terminals 15 (15 '), 16 (16'), 17 (17 ') are connected to the transistors 21 (21'), 22 via the resistors 18 (18 '), 19 (19'), 20 (20 '), respectively. (22 '), 23 (23') and connected to the base of each transistor 21 (21 '), 22 (22'), 23 (2
3 ') Collector (or emitter) with 2 resistors
Light emitting elements 1 ', 2', 3 'are connected in series with 4 (24'), 25 (25 '), 26 (26'). In addition, 27 (27 '), 28 (2
8 ') is a power supply terminal.

Transistors 21 (21 '), 22 (22'), 23 (23 ')
Thus, the light emitting elements 1 ', 2', 3 'are sequentially driven.

 However, no specific driving method is described.

 FIG. 15 is a schematic diagram of a conventional example.

A solid state light emitting element 1 'and a glass window 32
a, a glass window 32b is provided, and an object is illuminated with illumination light of the solid state light emitting element 1 ', and an image is formed on a CCD 34 via a lens 33.

The solid state light emitting element 1 'emits blue, green, and red light sequentially by a power supply circuit 35. The signal output from the CCD 34 is amplified by an amplifier 37 via a lead bundle 36,
The image is amplified by the blue, green, and red amplifier circuits 39B, 39G, and 39R via 38, and the subject image is displayed on the CRT 40.

The CRT 40 has horizontal and vertical polarization circuits 41 and 42.
Are input as horizontal and vertical polarization signals.

These horizontal and vertical polarization signals are generated by the oscillation output of the oscillation circuit 43.

The operation timing of the power supply circuit 35, the signal switching circuit 38, and the oscillation circuit 43 is controlled by the control circuit 44.

[Problems to be Solved by the Invention] The above publication, that is, Japanese Patent Application Laid-Open No. Sho 60-217327 or
In the conventional example such as 66188, there is no specific description about the driving means of the light emitting element, and it is considered that the following problem occurs.

To turn on a filament type light source such as a solid state light emitting device or an incandescent bulb, a DC or AC power supply must be supplied.

In the medical field of an endoscope inserted into a body cavity, its safety must be ensured.

That is, since electric power is supplied to the light source of the endoscope, it is necessary to be able to avoid the danger of electric shock (electric shock) by assuming a situation of electric shock.

If the power supply for lighting the light-emitting element is conducted to the metal part of the endoscope, a current that may stimulate at least the myocardium flows through the human body. Could cause a serious accident that would stop the operation. The electric shock (shock) refers to a sensation that the nerves and muscles of the human body are stimulated by an external current, and that the muscles become rigid and numb.

In particular, when an electric shock is given to the heart, the myocardium cannot move in an orderly manner, and an extremely dangerous phenomenon called ventricular fibrillation occurs.

In the above-mentioned conventional example, since there is no means for avoiding them or means for ensuring safety, it is difficult to realize a highly safe endoscope apparatus.

The present invention has been made in view of the above points, and an object of the present invention is to provide an endoscope apparatus which can ensure safety even if a power supply leaks into a living body during use of the endoscope. .

[Means and Actions for Solving the Problems] In the present invention, attention is paid to the characteristic that the degree of electric shock changes depending on the magnitude and frequency of the current.

In other words, when the peripheral number is low, an electric shock occurs even with a small current, whereas when the frequency is high, an electric shock does not occur even with a large current. This is because the higher the frequency, the lower the feeling of nerves and muscles. With a current of several hundred kHz or more, there is no danger of ventricular fibrillation even if a current of several hundred mA flows. Medical literature also reports that there is no problem at frequencies of about 300 kHz to 5 MHz.

Therefore, in the present invention, based on the above theory, by providing a driving means for driving the light source provided at the distal end of the endoscope at a frequency of about 300 kHz or more, even if a driving power supply leaks to the living body side, an electric shock may occur. Is provided to ensure safety.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to the drawings.

1 to 8 relate to a first embodiment of the present invention, FIG. 1 is an overall configuration diagram of an endoscope apparatus of the first embodiment, and FIGS. 2 (a) and (b) are video scopes, respectively. FIG. 3 is a circuit diagram of an LED drive circuit for driving an LED of a videoscope, FIG. 4 is a circuit diagram of an LED drive circuit for driving an LED of a fiberscope, and FIG. FIG. 3 is an operation explanatory diagram of FIG. 3, FIG. 6 is an operation explanatory diagram of FIG. 4, FIG. 7 is a characteristic diagram showing myocardial sensitivity to frequency,
FIG. 8 is a waveform chart showing a waveform example of the LED drive signal.

As shown in FIG. 1, the endoscope device 51 of the first embodiment
A video scope 52A and a fiber scope 52B; a power supply 53 for supplying illumination power to these scopes 52I (I = A or B); a video processor 54 for performing signal processing on the video scope 52A;
A first monitor 55 for displaying the video signal processed by the first and a television camera 56 that can be attached to the fiber scope 52B.
A camera control unit (hereinafter referred to as CCU) 57 for performing signal processing of the external television camera 56;
And a second monitor 58 that displays a video signal output from the CU 57.

The scope 52I has an elongated insertion portion 59, and a large-diameter operation portion 60 is formed at the rear end of the insertion portion 59. The video scope 52A has a universal cord 61 extending from the operation unit 60, and a scope connector 62 is attached to a tip of the cord 61. A signal cable 63 is further extended from the scope connector 62 so that the signal connector 64 can be connected to the video processor 54.

On the other hand, an eyepiece 65 is formed at the rear end of the operation unit 60 of the fiberscope 52B, and an external television camera 56 can be attached to the eyepiece 65. A light guide cable 66 extends from the side of the operation unit 60, and a scope connector 67 attached to the end of the cable 66 can be attached to the power supply device 53.

As shown in FIG. 2 (a), the distal end of the video scope 52A emits LE (red), green (G), and blue (R) light.
D68R, 68G, and 68B (represented by 68) are provided two each around the center CCD69. A channel 70 is provided adjacent to the CCD 69.

On the other hand, the tip of the fiberscope 52B is shown in FIG.
For example, LEDs 71a and 71b (represented by 71) that output, for example, white light as shown in FIG. A channel 73 is provided adjacent to the image guide 72.

The LED 68 or 71 is driven by the output of the LED drive circuit 75 that outputs a drive signal when the clock of the oscillation circuit 74 is input. The video scope 52A captures images in, for example, a frame-sequential system (accordingly, the CCD 69 does not have a color filter for color separation), and thus the LEDs 68 are sequentially turned on.

LED circuit 75a that drives LED 68 of this video scope 52A
3 is shown in FIG.

The reference clock output from the oscillation circuit 74 is input to the multiplexer 77. The three output terminals of the multiplexer 77 are connected to the bases of the driving transistors Q1, Q2, Q3 via resistors R1, R2, R3, respectively.
2, the emitter of Q3 is grounded, and each collector is LED6
8 and a resistor R4, an LED 68G and a resistor R5, and an LED 68B and a resistor R6 are connected to the power supply terminal Vcc.

The LEDs 68R, 68G, 68B are sequentially turned on via the multiplexer 77. In this case, a cable is connected from the video processor 54 to set the CCD69 charge readout period and timing.
A timing signal is sent to the oscillation circuit 74 in the power supply device 53 via 78, and the LEDs 68R, 68G, and 68B sequentially emit light in the R, G, and B colors by the drive circuit 75a to illuminate the subject.

In the LED drive circuit 75a, the three transistors Q1, Q2, and Q3 are sequentially turned on by the reference clock via the multiplexer 77, and the red, green, and blue LEDs 68R, 68G, and 68B are sequentially turned on. That is, as shown in FIGS. 5 (a), 5 (b) and 5 (c), the red, green and blue LEDs 68R, 68G and 68B are sequentially turned on. As shown in
R, G, B light is emitted. That is, the illumination can be performed in a frame sequential manner.

On the other hand, the LED driving circuit 75 in the case of the fiberscope 52B
b is the circuit configuration shown in FIG.

The reference clock is input to the comparator C1, and a binary signal compared with the 0 potential is applied to the bases of PNP and NPN transistors Q4 and Q5 via a resistor R7. Transistor Q
The emitter of the transistor 4 is connected to the positive power supply terminal Vcc via the resistor R8, the collector is connected to the collector of the transistor Q5, and two (equivalently) two white light emitters are output.
Grounded via LEDs 71a and 71b. The emitter of the transistor Q5 is connected to the negative power supply terminal -Vcc via the resistor R9.

The converter C1 outputs a signal of "H" while the reference clock is being output. In this case, the transistor Q5 is turned on, and the LED 71a emits light as shown in FIG. On the other hand, during a period in which the reference clock is not output, the transistor Q4 is turned on, and the other LED 71b is turned on as shown in FIG.
Emits light. Since the LEDs 71a and 71b are alternately turned on in this way, the temporary emission from the distal end of the scope is as shown in FIG. 6 (c). By the way, the sensitivity of the myocardium to the frequency is as shown in FIG.

That is, when the frequency is low, the sensitivity is high, and when the frequency is high, the sensitivity is low. Therefore, when the LED 68 or 71 is driven, it is desired that the influence on the myocardium and the like be small, assuming that the drive signal leaks to the metal portion of the insertion portion due to a failure or the like. Therefore, in the first embodiment, the frequency of the voltage or current of the drive signal, that is, the frequency f of the LED drive signal for lighting the LED 68 or 71 is set to about 300 kHz to 5 MH so that the influence on the myocardium can be reduced. I have.

The LED drive signal for driving the LED 68 or 71 may be a rectangular wave with f = 1 / T (where T represents a period) as shown in FIG. 8 (a), but FIGS. As shown in c), a sine wave may be used.

Also, as shown in FIG. 8 (d), the duty is changed by changing the pulse width t or the cycle T, and the LED 68 or 71 is changed.
The brightness may be adjusted by controlling the light emission intensity.

Note that the LED drive circuit 75 in FIG. 1 corresponds to L in FIG. 3 and FIG.
The ED drive circuits 75a and 75b are representatively shown. Therefore,
Switching may be performed by a switch or the like, or identification means may be provided in the scope connector 62 or 67 so that switching can be performed by determining which identification means is connected.

The LEDs 68R to 68B, 71a, 71b shown in FIGS.
Is actually provided at the distal ends of the scopes 52A and 52B as shown in FIG.

According to the first embodiment, the distal end of the insertion portion 59 is provided.
Since the frequency of the LED driving signal of the LED driving means circuits 75a and 75b for driving the LEDs 68 or 71 is set to about 300 kHz to 5 kHz, for example, due to the deterioration of the scope 52I, the jacket is broken and the internal LED driving signal line is Even if a situation occurs in which a part of the human body comes into contact, it is not a frequency band that will cause an electric shock to the human body, so it is possible to realize a highly safe endoscope system that does not adversely affect the patient, such as electric shock. become.

In the first embodiment, the LED driving circuit 75
The operation unit 60 in each scope 52I is provided.
Alternatively, it may be provided on the distal end side of the insertion portion 59 or the like.

Even in this case, even if the power supply portion of the LED drive circuit 75 of the scope 52I directly touches the patient, the danger during diagnosis or the like can be minimized, and safety can be ensured.

FIG. 9 shows a configuration of a lamp driving circuit 82 in the case where a lamp 81 is used instead of an LED. That is, for example, the LEDs 71a and 71b shown in FIG.
Instead, one or more lamps 81 are provided.

Thus, the lamp 81 is turned on by the lamp drive circuit 82 as shown in FIG. This lamp driving circuit 82
This is the same circuit configuration as the LED drive circuit 75b shown in FIG.

In the first embodiment, the video scope 52A is a frame sequential type, but it is apparent that the present invention can be applied to a simultaneous type video scope.

In the case of a simultaneous video scope, if the illumination means is the same as that shown in FIG. 2A, for example, the LED drive circuit omits the multiplexer 77 in FIG. May be applied to the transistors Q1, Q2, Q3 via the resistors R1, R2, R3.

Using this LED drive circuit, FIG. 10 (a),
As shown in (b) and (c), the LEDs 68R, 68G, and 68B are turned on and off at the same time. Therefore, the output light of the scope is
As shown in FIG. 3D, white light obtained by combining R, G, and B is emitted.

Further, in the first embodiment, the photographed subject image can be displayed on the second monitor 58 by attaching the external television camera 56 while using the fiber scope 52B. In this case, the external television camera 56 is a simultaneous type, but may be a frame sequential type.

The frequency of the driving signal for driving the lighting means is 5M
Hz or more may be used.

[Effects of the Invention] As described above, according to the present invention, the frequency of the drive signal for driving the illumination means provided at the distal end of the endoscope is set to about 300 kHz.
As described above, even if the drive signal leaks, it is possible to prevent the living body from being adversely affected.

[Brief description of the drawings]

1 to 8 relate to a first embodiment of the present invention.
FIG. 1 is an overall configuration diagram of the endoscope apparatus of the first embodiment, FIGS. 2 (a) and 2 (b) are front views showing the distal end portions of a videoscope and a fiberscope, respectively, and FIG. FIG. 4 is a circuit diagram of an LED drive circuit for driving an LED of a fiberscope, FIG. 5 is an operation explanatory diagram of FIG. 3, and FIG. 6 is an operation explanatory diagram of FIG. FIG. 7 is a characteristic diagram showing the sensitivity of the myocardium corresponding to the frequency, FIG. 8 is a waveform diagram showing an example of the waveform of the LED drive signal, FIG.
FIG. 10 is a circuit diagram of a driving circuit for driving an illumination lamp according to a modification of the first embodiment of the present invention. FIG. 10 is an explanatory diagram of an operation when LEDs are simultaneously turned on in the second embodiment of the present invention. 11 are front views of a solid state light emitting device, FIG. 12 is a plan view of FIG. 11, FIG. 13 and FIG. 14 are circuit diagrams showing a drive circuit, FIG. FIG. 1 is a block diagram showing a configuration of the endoscope apparatus. 51 Endoscope device 52A Video scope 52B Fiber scope 53 Power supply device 54 Video processor 55 First monitor 56 External television camera 57 Camera control unit 58 2 monitors, 74 oscillator circuit 75 LED drive circuit 68 LED 69 CCD 71a, 71b LED 72 Image guide

Claims (1)

(57) [Claims] 1. An endoscope apparatus comprising: an illuminating means provided in the vicinity of a distal end portion of an endoscope; and a power supply for outputting a driving signal for driving the illuminating means, wherein the frequency of the driving signal is set to about 300 kHz or more. An endoscope apparatus characterized by being set.